A cleaning device for hose filters comprising a cleaning head is known from EP No. 1 543 872.
The cleaning device described therein comprises a cleaning head on which at least one nozzle and in particular a plurality of nozzles are arranged rotatably about a longitudinal axis of the cleaning head. During operation, the cleaning head on a hose element is guided into a filter hose and is moved to and fro therein. A pressure medium is fed to the cleaning head via the hose element by means of a pressure medium source, which pressure medium emerges from the nozzles and impinges upon the inner wall of the filter hose. As a result, compression waves are generated in the filter hose, which bring about self-oscillations of the hose material so that a filtrate located on the filter hose drops down. During operation, as the pressure medium emerges from the nozzles, a negative pressure is produced in the vicinity thereof so that the cleaning head does not remain in the centre of the filter hose but is drawn to the inner wall of the filter hose. In fact, the hose element with the cleaning head describes a spiral movement along the longitudinal axis of the filter hose. Contact of the cleaning head with the material of the filter hose leads directly or at the latest after a few cleaning processes, to damage to the material. However, if a support cage remains in the filter hose during the cleaning process so that the cleaning head cannot impact against the material of the filter hose but against the support cage, the cleaning head becomes statically charged to that voltages of up to 2000 V to 3000 V are produced.
It is disadvantageous that in the aforesaid prior art during cleaning of filter hoses, contact of the cleaning head with the filter hose can lead to damage to the filter material. It is also disadvantageous that cleaning with an inserted support cage for protecting the filter material can lead to a considerable static charging.